I build marketing systems that actually run.
I’m Alve Castellanos — a digital marketing, MarTech, and CRO operator based in Switzerland. I’ve spent my career connecting traffic to conversion, and I now build practical AI agents for website growth and email capture.
Switzerland · operator
I work where strategy meets execution
Most of my work has lived at the intersection of marketing and execution: SEO and paid acquisition that has to convert, landing pages that have to perform, and the analytics and CRM plumbing that decides whether any of it counts.
The systems behind the campaigns
I’ve run marketing technology and CRM operations — HubSpot and Salesforce, migrations and automation, segmentation and data quality, and the website-to-CRM handoffs where good campaigns quietly leak.
Measured by conversion, not visibility
I care about what happens after the click: conversion analytics, landing-page performance, on-page intent, capture flows, and the quality of the subscribers and prospects a website actually produces.
Better decisions, not just more assets
The gap I keep seeing is between strategy and implementation. AI is good at generating more content; it’s still rare for it to make better decisions. So I build AI agents that turn website intent into strategy a marketer can actually use.
LeadsWithDemos
That work became LeadsWithDemos, a strategy-first email capture platform for content-led websites. It productizes one focused part of this: deciding what to offer, where, and to whom — before building another popup.
Swiss base, European context
I work from Switzerland, across B2B SaaS and European growth, in English and Spanish.
Let’s make your website growth more strategic
See the areas I go deep in, read how I think about marketing systems, or get in touch.